jenkins: don't build FFTW for performance runs
jenkins: don't build FFTW for performance runs

Since we don't even run accuracy tests, FFTW isn't used anyway.
ROCmSoftwarePlatform/rocFFT,ROCmSoftwarePlatform/rocFFT,ROCmSoftwarePlatform/rocFFT,ROCmSoftwarePlatform/rocFFT